WEP between Vendors

I just want to double check my understanding of WEP encryption beteen vendors. If you have a Cisco Aironet 1200 AP running 128-bit encryption then you need a Cisco provided access card (say the 350 series) in order to communicate at 128-bit. If you are using an “off” brand of access card then you would be limited to 40-bit encryption on the Aironet. Correct or not?

Thanks in advance for any comments…